Aging behaviors in AZ91D/Al18B4O33w composite fabricated by squeeze casting

Abstract

Aluminum borate whisker (Al18B4O33w) denoted by ABOw) reinforced AZ91D (Mg-9.1 mass%Al-0.7mass%Zn) magnesium alloy composite was fabricated by squeeze casting. AZ91D/ABO w composite and AZ91D alloy were aged at 443 K in oil-bath. The composite exhibited an accelerated age-hardening response comparing with AZ91D alloy. Age-hardening efficiency of composite was better than that of AZ91D alloy. It was attributed to the interfacial reaction between AZ91D alloy matrix and ABOw. The interfacial reaction increased aluminum elements in the matrix and MgO interfacial reaction layer restrained the formation of interfacial precipitate, resulting in more amounts of continuous precipitates and smaller inter-precipitates spacing within the composite matrix. © 2008 The Japan Institute of Metals.